212 



NATURE 



[December 15, 1910 



This statement is g^iven without comment or ex- 

 planation, and leaves us to draw the obvious inference 

 that coal-mining in the United Kingdom is attended 

 with considerably greater risk to the miner than is 

 the case with our French and Belgian neighbours. 

 To those who know the true facts, it is, however, by 

 no means certain that this .trreater risk in this country 

 is a real rather than an apparent one. It is a curious 

 fact that in no country does legislation define what is 

 meant by a fatal mining accident. In the United 

 Kingdom our inspectors have adopted a working 

 definition which answers all purposes, although devoid 

 of legislative sanction, and class as a fatal accident 

 any accident that directly or indirectly causes the 

 death of the victim within twelve months after the 

 occurrence of the accident. In Belgium, however, 

 only those accidents are considered fatal that directly 

 cause death within thirty days of the accident, whilst 

 in France, where no definition at all is attempted, an 

 accident is only classed as a fatal accident if it causes 

 directly the death of the victim, either on the spot or 

 at anv rate within a verv short interval of time, whilst 

 in Germany and Austria it would seem that for an 

 accident to be classed as fatal it must directly cause 

 immediate death. 



It is thus obvious that if the French or Belgian acci- 

 dent list were calculated upon the same basis as the 

 British, the death-rate in those countries might quite 

 conceivably appear to be higher and not lower than 

 our own. When the supreme importance of this 

 matter is considered, and when it is remembered that 

 every one of the countries concerned is engaged in 

 discussing legislation to promote the greater safety 

 of the miner, such legislation being not infrequently 

 based upon the comparative degrees of safetv as shown 

 bv the ratios of fatal accidents in the different coun- 

 tries, it is surely a pertinent question to ask whether 

 it is impossible to aij^ree upon an international defini- 

 tion of a fatal accident. 



Coming next to the statistics of production, a cer- 

 tain degree of uniformity has been attained by express- 

 ing all the outputs in metric tons. On the other 

 hand, however, there are unfortunately many different 

 methods in use for estimating the outputs. Begin- 

 ning with the first mineral on the list, namely, coal, 

 there are many sources of error in the apparently 

 simple task of recording the coal output. Even in the 

 United Kingdom the returns as between different 

 collieries are not comparable, the practice being here 

 to return as output the total weight of mineral drawn 

 up the shaft, regardless of the fact that this may con- 

 tain more or less stone. So that if of two mines, 

 which produce an equal quantity of coal properly 

 speaking, the whole of the stone is in one case picked 

 out below ground, whilst in the other a good deal of 

 picking is left to be done on a picking belt at bank, 

 the latter will be returned as producing more coal 

 than the former. Again, the question of colliery con- 

 sumption has to be considered ; a certain proportion 

 of the coals raised is used for the purposes of the 

 colliery itself, in order to generate steam for the 

 various engines at work, whilst in other cases, again, 

 some of the miners are supplied free with coal for 

 domestic purposes, this coal constituting in effect a 

 portion of their wages. It is obvious that it will 

 make a considerable difference in the output returns 

 if the colliery consumption under one or both of these 

 heads is included or excluded. 



The best plan w^ould probablv be to return onlv the 

 vendible coal as the output of a colliery, in which 

 case the coal supplied to the colliers, and in effect 

 sold to them as part of their wages, should be in- 

 cluded, but not that used for raising steam. More 

 important, however, is it to have a definite rule, which 



NO. 2146, VOL. 85] 



rule ought to be clearly and precisely set forth in the 

 returns; some legislative enactment on the subject 

 is obviously required. In Belgium the returns until 

 quite recently were always those of the coal raised 

 including stone; of late years some collieries have, 

 however, returned only vendible coal, whilst others 

 adhere to their ancient practice. In France the return 

 represents the vendible coal ^lus the colliery consump- 

 tion. In Germany the output returns comprise 

 vendible coal plus colliery consumption plus a certain 

 allowance for wastage. Further, it must be remem- 

 bered that on the Continent the coal itself is very 

 often not weighed, but its weip-ht is estimated from 

 the volume e.g. from the number of tubs of a known 

 capacity, produced by the mine. Here, again, it is 

 obvious that we are comparing figures which we have 

 no means of reducing to any uniform denomination, 

 and here, again, it is most important that there should \ 

 be an international agreement as to what is. meant by- 

 coal output. 



iMost countries assign a value to their coal produc- 

 tion, and in the introduction to the present report the 

 values of the coal outputs of some of the leading pro- 

 ducers of the world are tabulated. It is interesting to 

 calculate from this table the values assigned by the 

 various countries to their coal, the figures obtained 

 being as follows : — - 



United States ... 



Great Britain ... 



Germany 



Austria and Hungary... 



France ... 



Belgium 



It is obvious at first sight that these coal values 

 must be based on more or less arbitrary data, and 

 possess no scientific importance. Intrinsically French 

 coal is certainly not worth more than twice as much 

 as American coal; in fact, so far as absolute value 

 goes, the Ainerican coal, which is here returned as 

 the least valuable of all, is actually the most valuable, 

 as a large proportion of high-class anthracite enters 

 into the American production. Undoubtedlv the 

 determination of the value of a given mineral produc- 

 tion is a difficult matter, even if a precise definition 

 be adopted ; it would probably be best to take as a 

 basis the value of the mineral loaded up readv for 

 transport at the mine, or, in other words, its selling 

 price less the cost of transporting it to a market and 

 marketing it ; the only drawback to this mode of 

 valuation lies in the fact that the values thus assigned 

 may be liable to wide fluctuations in accordance with 

 the laws of supply and demand. Fortunately, it may 

 be said that of all the data contained in this report, the 

 monetary values of the mineral production are prob- 

 ably the least important. 



In some cases, improvements have been introduced 

 in the methods of stating the returns ; thus gold and 

 silver are now returned in kilograms of fine rfietal. In 

 many cases the output of metalliferous minerals is 

 stated, not in terms of the weight of ore, but in terms 

 of the weight of metal contained in the ores. The 

 heading in the report before us says, "contained in 

 or obtained from ore," but we assume that the latter 

 half of this phrase is an error. The figure that is 

 required is either the amount of metal contained in 

 the ore or else that obtainable from it, the two being 

 by no means equivalent statements. If the former is 

 adopted, it means the weight of ore multiplied by the 

 percentage of metal contained in it as determined by 

 accurate chemical analvsis, not bv so-called commer- 

 cial assav. If the latter method is adopted, the return 

 would give the amount of metal that can be obtained 

 from the ore by the smelting operations to which it is 



